Allright fellas please help a brother out ran boat today up to half throttle fine kick it in the but and dipstick blows out and oil everywhere???????????????????????!!!!!!!!!!!!!!!!! !

540ci with 1071 bds blowers

I'd do a compression test, or leakdown test... to find out which cylinder has the hole in the piston.

Like stated above do a compression test at the very least and if that doesn't show anything then do a leakdown test.

MAN THAT WASNT WHAT I WAS WANTING TO HEAR. Ive been reading and ive found alot of comments about ventilators stopped up? I put dipstick back in and crancked motor back up oil pressure holds good! I ran it back to dock bout 1/3 throttle power seems fine

Somehow compression is leaking into the crankcase when you are on it. Some is normal, but if this just started happening then what they said is correct, you need a compression test done to find out if you have a really weak hole, that will be your bad piston.

also have seen where people have said that high hp motors with blowers often require a latching mech. of some sort to hold dipstick in

Blower motors will push the dipstick out under big boost, but normally it does it from the start. Did this just start to happen or has it always done it?

it happened last time i went out to but thought it was a fluke just from checking oil thought didnt put dipstick all the way in. It only comes out about 2 inches. only reason i didnt think it was engine prob is no unusual sounds, good power, temps and pressures good!

If you have decent compression numbers then you can add a spring to the end of the dipstick. Use a small hoseclamp to hold the spring in place and then bend the end to wrap around the dipstick. There are also locking dipsticks for a cleaner look.

Make sure your exhaust is not going bad,I had a riser start going and this happened must have been getting some water in the cylinders and lowered compression.Fixed exhaust and it never did it again.